稀土掺杂纳米固体超强酸SO_4^(2-)/SnO_2-Eu_2O_3催化合成十六烷酸乙酯的研究  

Study on catalytic synthesis of ethyl palmitate by rare-earth-doped nanosolid superacid SO_4^(2-)/SnO_2-Eu_2O_3

作　　者：杨婷婷[1] 邓斌[1] 

机构地区：[1]湘南学院化学与生命科学系,湖南郴州423000

出　　处：《宝鸡文理学院学报（自然科学版）》2014年第4期15-19,32,共6页Journal of Baoji University of Arts and Sciences(Natural Science Edition)

基　　金：湖南省自然科学基金项目(No.12JJ3019);湖南省科技厅计划项目(No.2010GK3123);湖南省教育厅重点科研基金项目(No.10All3)

摘　　要：目的研究稀土掺杂纳米固体超强酸SO2-4/SnO2-Eu2O3催化剂对合成十六烷酸乙酯的影响,确定最佳反应条件。方法利用溶胶-凝胶法及改性技术制备稀土掺杂纳米固体超强酸SO2-4/SnO2-Eu2O3催化剂,并用单因素法研究催化剂的最适宜制备条件;采用正交试验来确定十六烷酸乙酯催化合成的最佳条件。同时利用熔点、红外光谱等手段对产品进行物性和结构表征。结果 Eu2O3的添加量为1.5%(指Eu2O3占SO2-4/SnO2的摩尔分数),硫酸浸渍液的浓度为2.0mol/L,焙烧温度为500℃,焙烧时间为2.5h条件下,制备出的SO2-4/SnO2-Eu2O3催化剂具有最好的催化活性。通过正交实验确定的酯化反应优化条件是:在80~85℃的回流反应温度下,醇酸摩尔比为5.0∶1.0,催化剂用量为反应物总质量的5.0%,反应时间4.0h,十六烷酸乙酯的酯化率可达97.0%以上。各种分析结果一致表明,催化合成所得之物与十六烷酸乙酯标准相符合。结论该催化剂具有良好的催化活性和重复使用性,反应条件温和,方法简便,酯化率高,具有很好的工业化应用价值。Abstract. Objective--To study the effects of rare-earth-doped nanosolid superacid catalyst SO42-/SnO2-Eu2 O3 on the catalytic synthesis reaction of ethyl palmitate and to confirm the optimal reaction conditions. Methods--The rare-earth-doped nanosolid superacid catalyst SO42-/SnO2-Eu2 O3 was pre- pared with sol-gel method and modified technology, and its suitable preparation conditions were stud- ied by using single factor method. The optimum conditions of the catalytic synthesis reaction of ethyl palmitate were determined through orthogonal experiments. Meanwhile, the property and structure of the products were characterized by MP and IR. Results--The catalytic activity of rare-earth-doped nanosolid superacid SO42-/SnO2-Eu2 O3 was best under the conditions that loading amount of Eu2 03 was 1.5% （based on mole fraction of Eu2 O3 in SO42-/SnO2 ）, the concentration of sulfuric acid solution 2.0 mol/L, calcination temperature 500 ℃ and calcination time 2.5 h. Orthogonal test results showedthat the optimal reaction conditions for synthesizing ethyl palmitate with SO42-/SnO2-Eu2 O3 were as follows, reaction temperature was 80～85℃ molar ratio of ethanol to palmitic acid was 5.0 to 1.0, the quantity of catalyst equal to 5.0 % the weight of the total reactants and reaction time 4.0 h. Under these condition, the esterification rate reached more than 97.0%. All analysis results showed that the catalyzed synthesis product was eonsistent with the ethyl palmitate standard. Conclusion The catalyst has high catalytic activity and good reusability. This method boasts mild reaction conditions, simple methods, high esterification yield and extensive utilization.

关 键 词：十六烷酸乙酯 催化合成 稀土 纳米固体超强酸 SO42-/SnO2-Eu2O3 

分 类 号：TS202.3[轻工技术与工程—食品科学]